Refrigerator



Feb. 22, 1938. w. w. WARREN REFRIGERATOR Filed July 3, 1936 2 Sheets-Sheet l ELECTRIC SUPPLY w. w. WARREN 2,109,002

REFRIGERATOR Filed July 5, 1936 2 Sheets-$heet 2 INVENTOR m w s 3. a z 1 2 4 5 IN a 3 4 C 5 m w I LE [M II 25 T a J 4 0 4 W 5 w 1. a .w v I l 7 i 535 twa n 5 3 Q/A w a m Feb. 22, 1938.

Patented Feb. 22,1938

UNITED STATES PATENT OFFICE REFRIGERATOR William W. WarrenQPittsburgh, Pa., assignor of gne-half to Stanton 0. Stimmel, Fox Chapel, a.

Application July 3, 1936, Serial No. 88,792- 11 Claims. (01.,62-89) My invention relates to the preservation of art. Suflice it briefly to say that the refrigeratfoodstufis and otherperishables, and consists in ing apparatus includes an, electric motor 9, a a refrigerator in which a condition of subatmoscompressor ID, a condenser ll, expansion coils pheric pressure is established and maintained. (not shown) enveloping a tray compartment l2 I have discovered that rarefied atmosphere opwithin chamber 3;and a thermostat l3 connected 5 erates in conjunction with subnormal temperavin the electric supply lines M of the motor, for ture within a refrigerator, to improve the preserautomatically controlling the operation of the vation oi certain perishables. The invention motor and compressor in accordance with temis particularly directed to improvements in meperature conditions within thechamber 3.

chanical refrigerators; as distinguished from re- In accordance with my invention, 1 rarefy the 10 frigerators cooled by ice. air within chamber 3, and, advantageously, I pro- In the accompanying drawings the invention, vide a rotaryexhausting pump [5 which is conby way of illustration and notlimitation, is illusnected in common with the compressor III to the trated in embodiment in a domestic refrigerator. 1 drive shaft of motor 9--a double-grooved pulley Fig. 1 is aview of the refrigerator, partly in front l6, belts H and, i8, and pulleys l9 and pro- 15 elevation and partly in vertical section; Fig. 2 viding such common driving connections. The is a fragmentary view, taken on the plane 22 of intake port of the pump communicates by way Fig. 1, and showing to larger scale and in vertical of-a duct 2| and pipe 2'2'with the chamber 3, and section a particular valve which is organized in operation the pump draws air from such cham- 20 with the usual door-latch of the refrigerator; and her and discharges it through anexhaust line 23 20 Fig. 3 is a view-comparable with Fig. 2, illustratinto the open atmosphere. Subject to automatic ing the valve in alternate position; Fig. 4is a diacontrolling means presently to be described, the gram, illustrating a modification in the electrical pump establishes the desired atmospheric rareflr. wiring of the apparatus shown in Fig. 1; Fig. 5 cation, or degree of vacuum, in the storage cham- I 25 is a fragmentary view, illustrating to larger scaleher 3, while in usual way the mechanical refrig- 25 and in vertical section a particular valve mechaerating apparatus establishes and maintains subnism embodied in the mechanical apparatusof normal temperature of predetermined degree. the refrigerator; and Fig. 6 is a view comparable Under such conditions certain perishables are with Fig. 5, illustrating particular parts of the more eflectively preserved. a

valve mechanism in alternate positions of service. In order to'perm'it the door 2 readily to, open 30 Referring to Fig. 1, aconventional refrigerator against the normally preponderant pressure of cabinet I is illustrated, and in usual way. a therthe outer atmosphere, I provide means for breakmally insulated door 2 affords access to the chaming the vacuum within the chamber 3. Such her 3 within the cabinet, in which perishables are means consistin a' cylindrical valve-chest 24 in- 35. stored. The walls of the cabinet are hollow, pro-' cludinga ported valve 25. The valve chest 24 is Viding a m veloping space 4 for a packmounted on the'door 2of therefrigerator in axial ing of rock-wool, cork, or other heat-insulating v alignment with the'latch-bolt 6,-and the valve 25' material. Alternately, the space between the is integrated with, or comprises a continuation of, walls may be evacuated of air, to provide the dethe latch-bolt. Passages 26 extend from the 40 sired insulation against heattransfer from the valve-chest '24 through the insulated body of 40 outer atmosphere to. the chamber 3. The door 2 door 2; and in the normal door-latching position is mounted on hinges 5 (-oneonly appears), and of latch-bolt 6, the handle 1 extends in the a latch-bolt 6, mounted on the door and'respondotted line position indicated in Fig. 2, and the sive to the turning of a handle I, is movable into valve 25"closes the passages 26, whereby the deand from engagement with a catch-element 8, sired vacuum may be maintained in chamber v45 mounted on the wall of the cabinet. 3 11'. being understood that the door 2 carries the In usual way mechanical refrigerating appausual peripheral gasket (not shown) that seals ratus is arranged to maintain the temperature the doorway of chamber 3 when the door is sewithin the chamber 3 at substantially the desired cured inclosed position. Upon swinging the 5 subnormal value. Such apparatus in this case handle I upward, to disengage-the latch-bolt 6 is installed above the chamber 3. The particular from catch-element 8 (cf. dotted line position of make of refrigerating apparatus is not of prime the handle in Fig. 3) the valve '25 is rotated, and concern; any of the known types may be emits ports 25a are moved into registry with pasployed, and the general principles of operation sages 26. Thus, the chamber 3 is vented to theare already understood by those skilled in the open atmosphere, and the pressure within the 55 I chamber is so far balanced with the pressure refrigeration alone is eflective.

without that the door 2 may be readily swung open. v 1 Before proceeding with a more minute consideration of the evacuating mechanism, it may be remarked that the entire chamber within the cabinet i need not-be evacuated. That is to say,

a compartment, constructed with hermetic, heatconducting walls, may be provided within chamber 3, and-such compartment may have an indi- 'vidualdoor, provided with an air-venting latch,

such as the one carried by the door 2. In such case, the suctiontube 22 of the pump I communicates with the internal chamber of the compartment, whereby the desired conditions of refrlgeration and atmospheric rarefication are maintained within the compartment, while without suchcompartment, but within chamber 3, Accordingly, a compartmentis provided for those particular perishables which are best preserved in chilled and rarefied atmosphere. The foodstuff requiring less specialized treatment is stored in the chamber 3 without such compartment.

The art is familiar with the general idea of enveloping a refrigerator chamber with hollow, evacuated walls, in order to obtain the desired insulation against heat transfer. My invention embraces aparticularly efiective refinement of this concept." The space 4 between the double, hermetic walls of the cabinet I communicates by way of a passage 21 (Fig. 1) with the chamber 3 (or with a compartment within) which is subject to evacuation by pump IS. The passage 2'! is normally closed by a spring-backed check-valve 28, and, in normal operation of the pump, the check valve is drawn open, whereby both the chamber 3 and the chamber-enveloping space 4 are exhausted. And when the vacuum (the subatmospherlc pressure) in envelope 4 approaches that in chamber 3, the spring-backed valve 28 automatically closes, so that the door 2 may be opened and closed at will, without destroying the heat-insulating vacuum in the envelope. As

will presently appear, the vacuum pump l5 operates automatically to restore the vacuum which is destroyed by opening the door 2 of chamber 3. That is to say, the pump operates automatically to maintain in chamber 3 a' vacuum of predetermined degree, and, of course, the refrigerating apparatus operates in known way to maintain subnormal temperature in such chamber. If the established vacuum in the -heat-insulating envelope is destroyed, as ,may

happen over a long period of. service (due to slow leakage and infiltration or air from the outer atmosphere), the valve 28 opens in response to the suction of the pump, and the desired vacuumin the envelope is automatically reestablished. By virtue of such structure, the hitherto proposed use of hollow, evacuated walls becomes feasible in domestic and commercial refrigerators.

Turning to a more detailed consideration of the evacuating mechanism, it will be noted that the inlet passage 2|, 22 of the vacuum pump l5 aioacoa of cylinder 3i at the point 2m, while the pipe 22 communicates with the bore of the cylinder by way of a passage 22a. A'tube 31; opening at one end into the outer atmosphere, communicates at its opDOsite end (31a) with said bore of the cylinder 3!. The energizing circuit 38 of the electromagnet 33 is connected to the same electric supply as energizes the motor 9, and in Fig. l the electromagnet circuit 38 is shown connected in parallel with the motor circuit I4. I provide a pressure regulator, or, more accurately, a vacuum regulator 39, which consists in a Bourdon tube 40 .(Fig. 5) communicating by means of a conduit 4| with the atmosphere within chamber 3. Two electric contacts, 42 and 43, are included in the electromagnet circuit 38; contact 42 is mounted on the housing of regulator 39, and contact 43 is mounted on the movable end of the Bourdon tube. in chamber 3, the Bourdon tube is so spirally dilated or radially expanded that the two con-, tacts 42 and 43 engage, and close the circuit 38 with the electric'supply. Thus, the electromagnet is energized, and the armature 33 is drawn When normal atmospheric pressure exists to and held in its lower position, as shown in ture within the chamber .3. Accordingly, when in such usual operation the thermostat l3 closes the circuit l4 and sets the refrigerating apparatus in motion, the vacuum pump I5 is driven. Suction is produced in duct 2|; the valve 29 (Fig. 6) rises in response to such suction, and, by way of passage 22, air is removed from chamber 3 and discharged into outlet pipe 23 (Fig. 1). When the atmospheric pressure within chamber 3 falls to desired value-that is, when vacuum of desired degree is established in chamber 3-the Bourdon tube" 40 radially contracts in known way, and separates the contacts 42 and 43. Thereupon, the energizing circuit 38 of theelectromagnet is opened, and-the spring 32 shifts the valve 30 intovits upper position (Fig. 5). As the valve 30 moves into such position, the check valve 29 closes, the passage 22:; is blanked by portion 30a of the plunger valve, and the inner end 31a of tube 31 is uncovered, permitting communication of tube 31 with the inlet duct 2| of the vacuum pump. Thus, after the desired vacuum is established in chamber 3, the pump l5, continuing in operation so long as the thermostat holds the refrigerating apparatus in active service, merely circulates air. at normal atmospheric pressure from the tube 31 to the outlet pipe 23. It will, of course, be manifest that, as an alternative of this specific operation, the pump may be run with exhausting efiect upon the chamber 3 after the desired vacuum has been established therein, but such operation manifestly requires an expenditure of electrical energy which is avoided or minimized by idly circulating air at atmospheric pressure in the manner mentioned.

So' long as the desired vacuum exists in chamber 3, my refrigerator will operate with only a nominal increase in' power consumption over ordinary mechanical refrigerators.

If it should so happen that the refrigerating cubes.

- 38-th e circuit remains closed, and the valve 30 remains in theposition illustrated in Fig. 6, until the refrigerating. apparatus is again set in motion and the desired vacuum has been estab- 'lished.

In Figs. Sand 6, it will be'perceived that an air passage 44 extends from beneath the valve 30 to the passage'zza, and anairpassage 45, 46 extends from passage 22a to a point above the valve, it being remarked that the armature 33 is so spaced from the internal wall 'ofthe electromagnet as to admit of the vertical movement of air. The provision of these passages eliminates any pneumatic resistance to the above-described operation of the valve 30;

In the electric wiring, as above described and as illustrated in Fig. 1, the energizing of the electromagnet 34 is controlled solely by the regu lator 39. When the-pressure rises to such value that the Bourdon tube closes the contacts 42 and '43, the electromagnet is energized, and shifts the valve 30 into the exhaust position shown in Fig. 6, regardless of whether or no the motor 9 of the refrigerating apparatus is in operation. In some cases it may be advantageous to have the valve 39 open only whenthe motor 9 is in (or is about to begin) operation, and in Fig. 4 I

illustrate a modification to this end. The enerwithin the regulator stand in circuit-closing engagement. In such manner the valve-shifting electromagnet is energized in synchronism with the motor 9.

It will be understood that, in the usual domestic refrigerator, water is placed in trays within the compartment l2 for the formation of ice The ice-cube compartment l2, even though provided'with a door, is not a hermetically sealed chamber, and it will be-understood that, evacuating the chamber 3 in the above-'- describedmanner, the compartment I2 is exhausted of air, whereby a quantity of water in the trays is evaporated before ice' forms. In accordance with natural laws, this evaporation results in the abstraction of heat both from the atmosphere within chamber 3 and from objects in thermal communication with the water and the atmosphere, and thus it is that the airexhausting' instrumentalities of my refrigerator are effective in aiding the refrigerating mechanismp'roper in establishing and maintaining the invention claimed.

thermostat responsive to temperature in said chamber for controlling such apparatus, the combination of a pump driven by said motor for establishing a vacuum in saidv chamber, and

means responsive to the pressure of the atmos- 5 phere in said chamber for controlling effective operation of said pump.

2. In a refrigerator including a storage chamber and mechanical refrigerating apparatus, in-

cluding a motor, for cooling such chamber, the 10 passage for establishing communication between 15 the inlet of said pump and the outer atmosphere.

3. In a refrigerator including a storage chamber and mechanical refrigerating apparatus, in'- cluding a motor, for cooling such chamber, the

combination of a vacuum pump driven by-said 20 motor, a passage communicating with the inlet of said pump for removing air from and estab-. lishing a vacuum in said chamber, and a by-pus passage for establishing communication between the inlet of said pump and the outer atmosphere, .25

and means for alternately opening and closing said passages.

4. In a refrigerator including a storage cham-" ber and mechanical refrigerating apparatus, in-

cluding a motor, for cooling such chamber, the 30 combination of a vacuum pump driven by saidmotor, a passage communicating with the inlet of. said pump for removing air from and estab-, lishing a vacuum in said chamber, and a by-pass passage for establishing communication between 35 the inlet of said pump and the outer atmosphere, and electromagnetic means for alternately opening and closing said passages.

5. In a refrigerator including a storage chamber and mechanical refrigerating apparatus, in- 40 cluding a motor, for cooling such chamber, the combination of a vacuum pump driven by said motor, a passage communicating with the inlet of said pump for removing air from and establishing a vacuum in said chamber, and a'by-pass 45 passage for establishing communication between a the inlet of said pump and the outer atmosphere, and electromagnetic means for alternately opening and closing said passages, an energizing circuit for said electromagnetic means, together 50 with an electric make-and-break device in said circuit responsive to the pressure of the atmosphere in said chamber.

6. In a refrigerator including a chamber to be cooled, mechanical refrigerating apparatus in- 55 cluding an electric motor, an electric circuit for connecting saidmotor to an electric supply, and a thermostat responsive to temperature in said chamber for controlling said circuit the combination of a vacuum pump, a' passage from said 0 pump to said chamber, a valve for controlling flow in said passage, and electrically operated means connected to said electric supply for controlling operation of said valve.

'1. In a refrigerator including a chamber tobe I 55 cooled, mechanical refrigerating apparatus including an electric motor, an electric circuit for connecting said motor to an electric supply, and,

a thermostat responsive to temperature in said chamber for controlling said-circuit; the combi- 70 nation of a vacuum pump, a passage from said pump to said chamber, electrically operated means for controlling flow in said passage, a circuit for connecting said means to said electric supply, and an electric make-and-breakdevice 75 responsive to the pressure of the atmosphere in said chamber for controlling said last-mentioned circuit.

8. In a refrigerator including a hollow walled chamber, apparatus for cooling said chamber, and a motor driven pump for exhausting air from said hollow walls, the combination of means for causing said pump idly to circulate air at atmospheric pressure when a vacuum of predetermined degree has been established.

9. In a refrigerator including a hollow walled chamber and apparatus, including an electric motor, for cooling said chamber, the combination of a pump driven by said motor for exhausting air from said chamber and said hollow walls, and means for interrupting the exhausting effect of said pump when a vacuum of predetermined degreehasbeen established in said chamber.

10. In a refrigerator including a storage chamber, mechanical refrigerating apparatus, including a motor, for cooling said chamber, and a thermostat responsive to the temperature in said chamber for controlling said apparatus, the combination of a pump driven by said motor for establishing a vacuum in said chamber, and means responsive to the pressure of the atmosphere in said chamber for controlling the efiective operation of said pump, the walls of said chamber being hollowand including an exhausting passage for establishing communication between said pump and the interior of said walls.

11; In a refrigerator including a storage chamber, mechanical refrigerating apparatus vfor cooling said chamber, an electric motor for operating said refrigerating apparatus, meansresponsive to temperature for controlling the energizing of said motor, the combination of a vacuum pump, a passage from the inlet of said pump to said chamber, and means responsive to the pressure of the atmosphere within said' chamber for controlling the exhausting eflect of said pump upon said chamber, said last-mentioned means including an electrically operated valve for controlling flow in said passage.

WILLIAM w. WARREN.

and electrical, 

